


The Superadvantures of Supermermaid and Batman!

by truc



Series: Superbatweek 2019 prompts [5]
Category: Batman - All Media Types, Batman and Robin (Comics), DCU, DCU (Comics), Superman - All Media Types
Genre: But he's still a mermaid, Don't take Seriously!, Golden Age shenanigans, Kal is a man, M/M, Mer AU, Parody, Wacky humour, characters randomly sing, crack on crack, half-fish Kryptonian, innuendos, offscreen sex scene, out-of-character characters, overly ridiculous, references to the Little Mermaid, superbatweek2019
Language: English
Status: Completed
Published: 2019-07-29
Updated: 2019-07-29
Packaged: 2020-07-11 11:44:49
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,805
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19927549
Author URL: https://archiveofourown.org/users/truc/pseuds/truc
Summary: "Holy spaghetti-o, Batman! Look at the news!"Bruce glanced at the television. And he saw the most absurd he'd ever seen in his life (and knowing his lifestyle, this was quite something).On-screen, there was a half-man, half-fish floating in the air with his top covered in a ridiculous blue spandex-type long-sleeved shirt with a red S and a red cape whipping in the wind. Below the thing's waist, fish scales were composing what could only be said to be a fishtail. Robin's horrifying crime-fighting suit looked normal compared to that fashion atrocity."What is that," Bruce hissed with disdain.Day 5 of the superbatweek2019 prompts: Mer AU





	The Superadvantures of Supermermaid and Batman!

**Author's Note:**

> Absolutely wacky story. Don't take any of this seriously. Please don't.

"Holy spaghetti-o, Batman! Look at the news!"

Bruce glanced at the television. And he saw the most absurd he'd ever seen in his life (and knowing his lifestyle, this was quite something).

On-screen, there was a half-man, half-fish floating in the air with his top covered in a ridiculous blue spandex-type long-sleeved shirt with a red S and a red cape whipping in the wind. Below the thing's waist, fish scales were composing what could only be said to be a fishtail. Robin's horrifying crime-fighting suit looked normal compared to that fashion atrocity.

"What is that," Bruce hissed with disdain.

"It's a mermaid!" Dick exclaimed with the childish joy that made Bruce regret almost half of his life's choices.

Pinching his nose, Bruce leaned back. "Mermaids are one of the dumbest human inventions. Fishes' respiratory and energy transporting's systems are incompatible with humans' bodies. Furthermore, a tail that long would be unsuitable to budge that upper weight."

"It's magic, Batman! It's a flying mermaid!"

"If it's anything, it's alien. That's the only way to explain how a human-like body would fit with a fish-like body like that," Bruce argued vehemently.

Dick excitedly jumped on the couch. "Let's go investigate, Batman! Supermermaid can be our ally in our fight against evil!"

Bruce cut a look to the news with a frown. "Supermermaid? He's a male."

Dick laughed and flapped his arms around. "He's a super... mermaid!" He started singing (off-key):  
" _Under the sea we off the hook_  
_We got no troubles_  
_Life is the bubbles..._ "

Bruce's hand passed over his face. Why was the world crazy? AND why had he decided that taking an overly-excited circus kid to his crime fights a great idea? What had he been high on?

***  
_On patrol..._

"Batman! The despicable drug dealers are dealing with unlawful drugs! Let's do a drug bust!"

Batman sighed. "If you scream what we intend to do, we lose the element of surprise."

Robin cocked his head, mildly confused. "You doofus, Batman! I'm a hyperactive kid decked in red, green and yellow! We're not ninjas- although it would be cooler if we were... Do you think I could be ninja-kid?"

Why had Batman even brought a kid with him for crime-fighting? He needed a distraction. Right. Well, considering the evil dealers had already scattered away without Batman's intervention, his plan had certainly backfired.

"Batman, Sir," a new voice interjected from the sky, "I've gathered all the evil-doers together and called the cops."

Batman glanced up. There he was in all of his appalling fashion grandeur: Supermermaid (why that name?). He even had a big naive smile and a ridiculous curl in his hair.

Batman looked back at the assembly of drug dealers. None of them was even restrained in any way. "...Is there a reason why you didn't tie them up?"

Supermermaid grinned while he pushed out his glorious abdominals out. "I told them I'd tattle-tell on them to their mothers if they didn't behave. Tying them up felt unnecessarily cruel."

Batman gaped in silence at the wacky tactics used by this outrageous man-fish (he was not calling him a mermaid!).

All hell then broke loose. AKA, Robin got a look at 'Supermermaid' and went a bit crazy, even by his (decidedly low) standards.

"OOOOOOOOOOOOOOOOOOOOOOOOOOOOooooooooooh! Is that...? Holy religious matrimony, Batman, that's Supermermaid! He's so much cooler in real life! Can I have a fishtail too? It'd go fantastic with my costume, don't you think?"

Supermer-no, Batman refused to use that name! The man-fish beamed at Batman's protege. "You're as fashionable as I am." Batman rolled his eyes. From where he was standing, that was emphatically not a compliment!

"Thanks, Supermermaid! Can I get an autograph on my Robin cape? I'd like to carry it with me every night!"

The man-fish hovered down and took out a sharpie (From where had he taken the sharpie!?!) and scrambled the name 'Kal-El' in a nice calligraphy.

Batman scrunched his eyebrows together. "Your name is Kal-El?"

The man-fish looked startled. "How did you know?"

"...You wrote it on my protege's cape."

Supermermaid flashed his teeth. "I had heard tales of how you were the greatest detective alive. By golly! This feat is even more incredible than I thought possible!"

Robin crossed his arms and nodded. "He's only this awsome with my help."

Batman had the irrational need to tear his hair (even if it was under his cowl). What was wrong with them both?

Supermerm- No, the man-fish coughed and looked embarrassed.

"What's wrong?" Batman asked, unsure he wanted to know.

The man-fish blushed and averted his eyes. "I've always wanted to meet you, Batman."

What?

"Sickeroe! He wanted to meet you too Supermermaid!" Robin unhelpfully exclaimed.

Was it written somewhere that Batman needed to acquire the most embarrassing sidekick ever?

The man-fish's blush deepened and his fishtail wiggled a bit. How was that still working out of the water, Batman had no idea. "I'm... honoured..."

Batman decided to put an end to this useless conversation. "Robin, it's your bedtime. Let's go home."

Supermerm- The man-fish caught Bruce's arm. "Wait. Can we talk? I want to get to know you better, Batman, Sir."

Robin, being the worst of the devil's spawn that ever graced Earth, decided it was time to be 'tactful.' "Seeing how you are going to fluffy up together, I'll head up to bed first."

Fluffy up together? What was that even supposed to mean?

Robin yelled "Tarzaaannn," as he jumped off the roof.

The man-fish looked at Batman through his eyelashes. "Maybe... we should get to somewhere a bit more... private."

Before Batman could even retort that was the last thing they needed, he was bride carried to a new location: an inhospitable warehouse by the water.

"Down," Batman barked and the man-fish reluctantly let him go.

Batman brushed his armour off. He eyed the strangely docile yet energetically dog- he meant fish. The least he could do was get answers.

"Are you an alien?"

Super- The man-fish blinked. "Yes."

"Good." Batman had been right! He was going to push it down his annoying protege's throat until he choked on it.

He pondered for his next question for a while. The man-fish's nervous activities substantially increased in the meantime.

Batman pointed to the top and bottom. "How does your respiratory system even manage? Don't tell me it's a hybrid system."

The man-fish shrugged. "It's magic?"

Batman frowned at that. Robin was sure to rub it in his face. "Where are you from?"

The whatever-that-is-man's eyes brightened up. He clicked his fingers and the rare lights in the area went ominously out.

Then, the man-fish started to sing in the most harmonious voice Batman had ever heard.

" _I'm from Krypton, an ocean planet, far, far away from here._  
_The algae were green; the water, transparent and pure and; love shone brighter than bright._  
_Rao, our biggest moon and also our God, proudly glowed at us._

 _However, as oft happens, in paradises, avidity wrecked everything._  
_A seed of it was planted in the heart of the proudest Kryptonians._  
_They yearned to steal Rao's glow for their selfish use._

 _My father tried to dissuade them,_  
_But rebel against our fate they did._  
_They flew to the moon and stole Rao away._  
_Rao died, placing a curse against their cupidity._  
_No Kryptonian could live on Krypton ever again._  
_Foolishly, they ignored his warnings._  
_The planet fell to pieces; my father sent me away._  
_My spacecraft landed in the middle of the sea,_  
_where two algae farmers from the outskirts of the city of Atlantis took me in._  
_They raised me as their own, even though I had a tail._  
_When I began to be an adult, I swan away to see the world._

 _One night, I heard the most amazing sounds._  
_Pow! Bang! Poof! Pow! Bang! Pow! Pow! Pow!_  
_It was the sound of my beating heart!_  
_Lo and behold, upon that fairy alighted deck,_  
_I spied the one for whom my heart had raced._  
_He was a furious and snarling ball of black fury._  
_True love, indeed, it was._  
_Who else would accept a half-man, half-fish entity?_  
_The Batman, a half-man, half-bat seemed a real catch!_ "

Supermermaid- noooo!- had ended his song with a flourish. He stared at Batman, hoping for a reaction.

Batman closed his mouth and applauded. It was better not to upset such a capricious being!

Supermermaid bowed and floated closer, his tail swaying seductively.

"I've heard," he whispered, "that bats were also more attuned to oral pleasure. That would be splendid if it were true."

Batman heard himself swallow. "Why?"

Supermermaid's lips were an inch away from his when they answered. "I'm somewhat limited in my repertoire." His tail wiggled.

Batman licked his lips and Supermermaid's eyes hungrily ate them. "I don't think that's going to be much of a problem," Batman answered.

Supermermaid brought his lips to the feast...

(Tasteful fade-off.)

****  
_Later that evening..._

Batman's good mood abruptly disappeared when he saw Robin eating his milk chocolate sponged corn flakes over his million-dollar computer.

"Robin!"

Robin jumped and his bowl spilled on the computer. At Batman's aghast look, Robin took his cape and cleaned up the mess. "You were right, Batman, the cape is useful!" Great, more cleaning for Alfred. He was sure to get extra sassy.

"Aren't you supposed to be in bed by now?"

"Aren't you supposed to tuck me in bed?" Robin parroted back.

Robin sprang up. "Besides, who can sleep after they just met their idols?"

"This morning was the first time you even heard of his existence."

Robin threw his hands up. "He's so cool; he's practically Arctic ice!"

"Robin, time to sleep."

Robin pouted. There was nothing on Earth that could resist his pouts. Maybe Supermer- Kal could, Batman thought. That would be mighty helpful.

"Well," Robin added when he saw he had won the argument, "what do you think of him?"

Batman thought back to the tail end (quite literal) of his evening. "He's... very determined and convincing. He can see through objects with his eyes and he can use his mouth to unleash dangerous attacks. He's also very coordinated. He also showed me how deft he was with his hands. He has a lot of range in strength and its precision cannot be overstated."

"Wack-a-moley, guacamole, Batman! We got a new ally!"

Batman shook his head. "He has such a talented silver-tongue I'm not sure I believe everything he told me. I will have to keep a very close eye on him."

Robin rubbed his eyes.

"Time to sleep, little Robin."

Robin only vaguely nodded as he walked upstairs accompanied by his guardian. "But... He's at least your friend, right?"

"For sure, Robin. He's a very special kind of friend."

After a slight pause, he added, "After all, it's not every day you befriend a mermaid."


End file.
